I did some reading, but saw nothing about using cats with longtubes...

My idea is this: 3" cutouts(or same size as collector, its been a while since I dug the hooker longtubes outta the garage) directly off each collector, then 2 1/4 reducer to 2 1/4 cat on each side, custom fabbed y-pipe similar to mufflex's design, then we all know how it goes from there.

Ok, by now your probably sayin "Why?" Well, I got the Hooker super comps for $70. Second, NJ is starting alot of spotchecks now, and I sure as hell dont wanna be caught with out cats, the fine is insane. I know its going to be pretty restrictive, however with the cutouts open for racing it should be just fine, and closed should be nice and dosile for street/daily use. Im sure clearance will be quite limited, but I wont know for sure until the engine and headers are in there.

Any input?

 

There's no particular reason for the cats to be restrictive. I'd use 2-1/2", though.

One small detail: In order to be "legal", they have to be in the same location the factory put them. Get the car up in the air, get an idea where the collectors will dump, and imagine the routing to get the pipes over where the factory put them.

If this is going to be a street driven car, you'd be better advised to sell the long tubes for whatever you can get out of them and buy some shorties with y-pipe that routes the exhaust to the cat where it is supposed to be. You've got to have a lot of engine to restrict such an aftermarket system designed for '86-'90 single-cat TPI.

If you're set on a cut-out, put it just before the cat so the bend of the "Y" of the cut-out goes to the cat and the straight part (to which you'll attach the cap) points straight out the side of the car.